The proposed work is comprised mainly of studies related to the biosynthesis of glucagon, to the structural comparison of glucagon-related peptides from a variety of tissue sources and to the actions of glucagon in maintaining normal fuel metabolism. Efforts will be made to induce and characterize a glucagon-producing tumor in experimental animals which would be especially useful in studies of biosynthesis. Antisera directed towards specific portions of the glucagon molecule will be used in order to probe the structural relatedness of intestinal, pancreatic and other glucagons. Electrophoresis, gel filtration and selective degradation procedures will be employed in the comparison of peptides reacting with specific and non-specific antisera. In addition, studies on the importance of glucagon in maintaining normal body and cellular function will be approached.